This proposal requests the purchase of instrumentation for parallel processing of data resulting in complex model estimations that have not been feasible with existing resources. The proposed computer hardware and software will be used by 18 NIH-funded research projects at the Carolina Population Center (CPC) at the University of North Carolina at Chapel Hill (UNC). These projects presently use or have the potential to use programs, written by statisticians and econometricians, that estimate limited dependent variable model, estimate discrete time hazard models, and/or provide correction for sample design effects. These programs would benefit from the latest RISC workstation-Powerserver technology configured in tightly coupled cluster for parallel processing to address advanced analysis needs. Parallel processing will result in a major change in the analyses of data providing estimation capabilities heretofore too expensive and too slow for routine use. The purchase of such equipment and software is not feasible from individual research grants because of cost considerations, but is ideal for use as a shared resource in the interdisciplinary research setting that CPC provides. The proposed powerserver cluster will provide a quantum enhancement in performance over other existing equipment currently available at CPC or elsewhere at UNC. While the use this instrumentation will be of particular use to established researchers, it will also benefit junior faculty in their pursuit of R01 funding for their research. These faculty often do not have the grant portfolios to either pay large mainframe costs for CPU- intensive jobs or to purchase desktop power of the type needed for simulations and estimation techniques. A support system of hardware, software, and programming and statistical expertise would be invaluable in preparing the new generation of researchers. The proposal demonstrates the ability of the Computer Services Unit and Statistical Unit at CPC to install and take full advantage of this instrumentation, the commitment CPC has to provide ongoing support and maintenance for the new systems, and the planned use and administration of the equipment.